It is possible to fully recover after a successful therapy. Men usually do not tell their partners about their crime. Therefore many women have relations with such men.
The sex drive usually is reduced with age. And with less sex drive, there is less drive to commit sex crimes. There are also medicines which reduce the sex drive and are used for men who have committed sex crimes. Such medicines do not prevent a normal sexual life, they just reduce an overly strong sex drive, which the person himself wants to get rid of.